/*
 * Copyright 2016 The Cartographer Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CARTOGRAPHER_SENSOR_INTERNAL_COLLATOR_H_
#define CARTOGRAPHER_SENSOR_INTERNAL_COLLATOR_H_

#include <functional>
#include <memory>
#include <vector>

#include "absl/container/flat_hash_map.h"
#include "absl/container/flat_hash_set.h"
#include "cartographer/sensor/collator_interface.h"
#include "cartographer/sensor/data.h"
#include "cartographer/sensor/internal/ordered_multi_queue.h"

namespace cartographer
{
    namespace sensor
    {

        class Collator : public CollatorInterface
        {
        public:
            Collator()
            {
            }

            Collator(const Collator &) = delete;
            Collator &operator=(const Collator &) = delete;

            void AddTrajectory(int trajectory_id, const absl::flat_hash_set<std::string> &expected_sensor_ids,
                               const Callback &callback) override;

            void FinishTrajectory(int trajectory_id) override;

            void AddSensorData(int trajectory_id, std::unique_ptr<Data> data) override;

            void Flush() override;

            absl::optional<int> GetBlockingTrajectoryId() const override;

        private:
            // Queue keys are a pair of trajectory ID and sensor identifier.
            OrderedMultiQueue queue_;

            // Map of trajectory ID to all associated QueueKeys.
            absl::flat_hash_map<int, std::vector<QueueKey>> queue_keys_;
        };

    } // namespace sensor
} // namespace cartographer

#endif // CARTOGRAPHER_SENSOR_INTERNAL_COLLATOR_H_
